Discrete - Time Chaotic Coders for Information

PART 1: SYSTEMATIC STRUCTURAL DESIGN Marco G otz, Kristina Kelber, Wolfgang Schwarz Technische Universit at Dresden Institut f ur Grundlagen der Elektrotechnik und Elektronik Mommsenstra e 13, 01062 Dresden, Germany [email protected] ABSTRACT This paper deals with the systematic top down design of discrete-time coder systems for information encryption. From the axioms, that the coder should be a maximally disturbed but invertible channel (according to the information signal) a general structure containing a static nonlinearity and a dynamical subsystem is derived and their system characteristics are speci ed. It turns out, that the encoder necessarily has to exhibit chaotic behaviour in order to satisfy the design axioms. Design examples are given and privacy / secrecy as well as the reliability under the condition of a weak disturbances are discussed. Realisation problems are considered in Part 2 [5] of this paper.